Big T
Well-Known Member
Not liking what I’m seeing with the valve cover girdles. Maybe the cork gasket would be better under the valve cover and the girdle directly on the valve cover? Or no gasket at all and girdle directly on the valve cover?
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What did you do with your GMT400 today...or yesterday....
- Thread starter deejaaa
- Start date
dbrannon79
I'm getting there!
Did I miss something on the girdles? an extra gasket between the rocker cover and the girdle ??
as for the cork gaskets, wouldn't the fitted rubber be a better option here for the rocker covers. I thought someone mentioned there was one made that has those little crush spacers made into the gasket to prevent it from squishing down too far and make an even amount of clamping force all the way around the surface.
as for the cork gaskets, wouldn't the fitted rubber be a better option here for the rocker covers. I thought someone mentioned there was one made that has those little crush spacers made into the gasket to prevent it from squishing down too far and make an even amount of clamping force all the way around the surface.
dbrannon79
I'm getting there!
Well just added a can of 134 to my AC on my truck. compressor had been cycling a little too often for my liking even though it was still cooling some. I figured it was a little low due to my compressor that I found leaking a while back. still seems to hold up for a decent while before I have to add some.
What puzzled me is just before I added anything to it I let the AC run a bit with the high idle on and my gauges connected. pressures started to rise on the high up around 325 psi but my fan hadn't come on yet...
still cooling around 65 on the temp dial in the vents so I gave it some throttle and nothing. grabbed my test light to check if the fan controller had went kaput. by the time I got the test light ground lead connected the fan came on. looked at the gauges and the high side was at 350 and then dropped down to 225 with the air flowing. Low side was sitting at 25 by then too. played with it some to get the fan to cycle on and off again but it started working like it is supposed to. had to look up the specs for the fan pressure switch, 280 - on and 210 - off.
not sure if the pressure switch was stuck from sitting without use till recently or what. I know I need to replace the compressor but am trying to baby it till it can't no more. it's only 87 degrees out now and after adding the one can it went from blowing 65 to darn near 40 deg in the vents.
Just strikes me as odd that the pressures had to get that high for the fan to come on at first.
What puzzled me is just before I added anything to it I let the AC run a bit with the high idle on and my gauges connected. pressures started to rise on the high up around 325 psi but my fan hadn't come on yet...
still cooling around 65 on the temp dial in the vents so I gave it some throttle and nothing. grabbed my test light to check if the fan controller had went kaput. by the time I got the test light ground lead connected the fan came on. looked at the gauges and the high side was at 350 and then dropped down to 225 with the air flowing. Low side was sitting at 25 by then too. played with it some to get the fan to cycle on and off again but it started working like it is supposed to. had to look up the specs for the fan pressure switch, 280 - on and 210 - off. not sure if the pressure switch was stuck from sitting without use till recently or what. I know I need to replace the compressor but am trying to baby it till it can't no more. it's only 87 degrees out now and after adding the one can it went from blowing 65 to darn near 40 deg in the vents.
Just strikes me as odd that the pressures had to get that high for the fan to come on at first.
Will L.
Well-Known Member
He explained that. Skip to the 10:00 mark for it.
The valve cover is so uneven and thin in places that the secondary gasket is to help put the load evenly around the surfaces.
The GM design is just crap. They made the metal too thin so they made the uneven surface design to clamp just the edge tighter. Factory original leaks under warranty were stupid common. Seriously when the GM field reps would come out, mechanics would get fired that day and many went to jail for assaulting the guy.
You think it aggravates you- try it when you are doing the same truck for the third time for free and putting on new covers is not allowed. Mechanics would sometimes buy the covers themselves, loosing $ for a week to deal with one truck. Ive seen guys jb weld a flashing inside the cover to get the oil to bypass the gasket area. One guy confessed to jamming a dab of silicone into each pushrod to stop oil flow from coming up so the truck would leave and he made $ for a month then quit to work elsewhere. That was at a dealership!
I got good at it but I was 100% clear that any leaking gaskets on these and a couple other engines with bad designs- I refuse to work on or was not responsible for leaks.
I always tried my best but it was horrible. Especially with “GMS” (GM Silicone) their official part number back then. We called it Gooey Messy Shittt.
Years later when I learned about “the right stuff” it helped a ton. Mechanics would just buy that themselves and bring it in.
Big T
Well-Known Member
But the cork gasket apparently allows for irregular compression when the girdle is torqued down as per Marty’s experience. Thus it would seem better to place the gasket under the valve cover (or no gasket at all) and the girdle directly on top of the valve cover.
Will L.
Well-Known Member
A gasket on both sides is probably the best with this girdle. Go look how narrow these two levels are on your cover. It is really skinny. So a gasket will squish on the high part and help spread some of the load to the lower part. Compare area marked blue vs red.
Realize the girdle covers both.
This has been a seriously annoying problem since the 80’s. I wanted to punch out the engineer of this a long time.
I wish the engine was more popular so that aftermarket companies would make some cast aluminum valve covers to eliminate it.
Realize the girdle covers both.
This has been a seriously annoying problem since the 80’s. I wanted to punch out the engineer of this a long time.
I wish the engine was more popular so that aftermarket companies would make some cast aluminum valve covers to eliminate it.
MrMarty51
Well-Known Member
Last edited:
MrMarty51
Well-Known Member
I was trying the two gasket system, one gasket between cover and head and the other gasket atop of the cover.
I thought all was well, using Honda Bond for a sealer.
Let it set for a while and came back. There was sealer had run from under the rocker cover and onto the exhaust manifolds, also a spot or two of oil, from the breather compartment within the valve cover, RH side. I knew there would be no sealing once oil had flowed a channel. Removed the cover, the gasket and then let the cover set, olen side down so it could finish draining oil out of the CDR chamber.
Went back together with the right stuff, gasket on top of cover then got too carried away with the torque.
It is straightened out now and I did have another gasket and put the new gasket under the girdle. This time snugged them nuts down nicely and it should be good to go now.
After I get the injectors installed, put the pipes to them and then I’ll fire up the engine, run it at a high idle for probably a half an hour or longer to be assured there will be no oil leaks from under them covers.
MrMarty51
Well-Known Member
Oh yeah. When I first got this truck. New injectors and new GPz.
I saved the GPz I removed. Had them in the boxes, in the box, in my tool box.
Someone in the forum was quite penniless and needed a set of GPz so I sent that set to that person.
I guess now I’ll have another set for such an emergency.
Big T
Well-Known Member
How much is too carried away with the torque? Spec is 16 ft lbs.
Big T
Well-Known Member
My experience is that they leak on the lower corners, especially the rear. The passenger side one is a pita to get it without wiping off sealant. Probably better to apply sealant to the head side. I still think girdle directly on valve cover, then maybe gasket underneath, would be the best way to go.
jrsavoie
Recruit
Be careful where you buy from .Oh yeah. When I first got this truck. New injectors and new GPz.
I saved the GPz I removed. Had them in the boxes, in the box, in my tool box.
Someone in the forum was quite penniless and needed a set of GPz so I sent that set to that person.
I guess now I’ll have another set for such an emergency.
Counterfeit glow plugs are or at least were an issue
MrMarty51
Well-Known Member
Got these from NAPA, AC/Delco, boxes marked made in Germany.
Might not mean anything but it shore looked good.
dbrannon79
I'm getting there!
@MrMarty51 did you get your issues sorted out on the new injectors? the few that were pissing streams?
MrMarty51
Well-Known Member
Not yet. The injector tester I was building from a couple of old jacks would not pump past about 500 PSI. Gave up on those and ordered in one of them made in India affairs.
I hope that one of the provided injector pressure tubes fits the 6.5 Bosch injectors.
If not then I’ll scrounge a swagelok high pressure ferrel fitting that will fit both sizes of tubes and and build something that’ll fit.
That pump is suppose to be here from India between the 28th and the 4th according to Amazon.
If this pump dont work then I’m getting on that VW site and ordering in one of theirs. I think they was about $250.00 or some such.
Might have to get into the injector setting buidness to pay for alla this
.
MrMarty51
Well-Known Member
I have had an old beam type inch pound torque wrench for years.
I have most always been able to get it in and make it function wherever I have had a need for it.
With the right side inner fender removed I was able to get enough swing to make it work to torque the GPz on that side.
Come down to torquing the glow plugs on the left side and decided I was not going to try and scruch and twist to read that beam scale.
Ordered in one of these 1/4” drive inch pound torque wrenches from our local Oriellys. About $35.00. I dont understand why I had not done this years ago.
Just a whole lot more convenient.
It is made in Taiwan but seems to be made of some mighty good material and well constructed.
And while I had the GP wires/terminals unplugged and handy, removed the plasticated end pieces, scrubbed the wires, terminals and plastic insulators with mineral spirits and B&P cleaner then scrunched down the terminals for a tighter fit and then plugged them all back in.
The right side center two wires a little more tricky.
With the heat shields removed, poke the wires through the shield tube, plug in the terminals to the GPz then install the heat shields back onto their perspective studs.
I have most always been able to get it in and make it function wherever I have had a need for it.
With the right side inner fender removed I was able to get enough swing to make it work to torque the GPz on that side.
Come down to torquing the glow plugs on the left side and decided I was not going to try and scruch and twist to read that beam scale.
Ordered in one of these 1/4” drive inch pound torque wrenches from our local Oriellys. About $35.00. I dont understand why I had not done this years ago.
Just a whole lot more convenient.
It is made in Taiwan but seems to be made of some mighty good material and well constructed.
And while I had the GP wires/terminals unplugged and handy, removed the plasticated end pieces, scrubbed the wires, terminals and plastic insulators with mineral spirits and B&P cleaner then scrunched down the terminals for a tighter fit and then plugged them all back in.
The right side center two wires a little more tricky.
With the heat shields removed, poke the wires through the shield tube, plug in the terminals to the GPz then install the heat shields back onto their perspective studs.
I did my door pins as well. I had to grind a little off to get it to go in.thought i'd start this thread with... What did i do...
replaced the door roller hinge thingy....
went from this:
to this:
still creaks when i open the door but i will straighten it out.
couldn't figure out how to drive the pin all the way.
also got this in the mail:
hard to see at night:
but i will get pics when the sun comes up.
hope you like the thread.......
Delete the vacuum pump. I replaced mine and it gave out less than 30k. Just get a smaller belt and a manual waste gate.this
to this
Do the part in the door that catches the pin. I replaced my pins and door seals. Still has play but it’s much better.
MrMarty51
Well-Known Member
You can load pics into Your posts directly from Your phone, camera or card.
Tap the attach files below and left of the post reply box. There will be a menu. Being i do most posting from my ohone I have most already taken a pic and choose photo library. Tap the pic then at the top of the library box tap the add button.
After the pic is loaded then another small menu, insert and choose full image.